Seismic waves are generated by the sudden release of energy in the Earth's crust that creates a vibration or wave motion. Fault lines are zones of weakness in the Earth's crust where rocks have fractured or broken, and they are often associated with earthquakes. When tectonic plates move, they can become stuck at their boundaries, building up strain and pressure along the fault line. When the stress becomes too great, the plates slip, and the energy released by this movement generates seismic waves.

The point on a fault where the rupture begins is called the hypocenter, and the point on the surface directly above the hypocenter is called the epicenter. From the epicenter, seismic waves propagate in all directions, traveling through the Earth's layers and causing the ground to shake. The nature and intensity of the seismic waves depend on several factors, including the size and location of the earthquake, the type of fault involved, and the geological structure of the area.